Improvement in safety-valves



UNITED STATES PATENT QEEICE.

FREDERICK HARDEN, OF CONSHOHOGKEN, PENNSYLVANIA.

IMPROVEMENT IN SAFETY-VALVES.

Specification forming part of Letters Patent No. 78,280, dated May 26, 1868.

To all whom it may concern:

Be it known that I, F. HARDEN, ofConshohocken, in the county of Montgomery and State of Pennsylvania, have invented a new and Improved Safety-Valve; and I do hereby declare that the following` is a full, clear, and exact description thereof, which will enable' those skilled in the art to make and useA the same, reference being had to the accompanying drawings forming a part of this specication.

' This invention relates to an improvement in'safety-valves, whereby they are made much more sensitive and sure in their operation than those hitherto in use. And it consists in lthe employment of two valves of dilferent diameters, and arranged as will be hereinafterv described.

The drawing is a longitudinal section of the arrangement, showing the position of the valves in the shell, and the manner in which the weight connteracts the pressure of steam.

A is the shell, which is connected with a steam-boiler or other vessel by the pipe B.

G is the upper valve. D is the lower valve.

E is the rod connecting the two.

The upper valve opens upward against the atmosphere.

The lower valve opens upward against the pressure of steam in the shell.

It will be seen that the diameters of these valves vary, so that the upward pressure of the steam may be counteracted by a weight operating on the valves. The diameters of the valves will be determined by the amount of weight employed, and the pressure oi' steam valve acts as a weight.

F is a cup which surrounds the lower end of the shell for steadying the valves.

The weight is attached to the ri'ng G, and may be more or less, according to `the pressure required. By retaining the same relative proportions between the valves, the safetyvalve can be applied with equal advantage to large and small steamboilers. The valves will not rise until-the steam-pressure overbalances the weight, and as soon as the pressure is reduced they close instantly.

This safety-valve is applicable to hydrostatic presses, and to pumps and pipes, and in all cases where it is desired to control the pressure of Vapor or fluids within given limits.

Itwill be seen that this valve is so simple and cheap in construction that it possesses, in this respect, a great advantage over all other known valves.

Having thus described my invention, I claim as new and desire to secure by Letters Patentrlhe arrangement oi' the cap F and weighted ring G, with relation to the stem E, and the valves C D of dicerent diameters, as herein described, for the purpose speciied.

FREDERICK HARDEN.

Witnesses GEO. CHUENsIDE, WM. HAYWooD. 

